This is only true for the merge request workflow and not at all a problem for the patch workflow, which can work entirely via email (and is in my eyes simpler). Have a look at https://git-send-email.io/ if you want to learn about it. This is the true decentralized spirit of git. :)
There are many good replacements, you just need to stop using Github :)
Some examples: Forgejo/Gitea (self-host or hosted eg. codeberg.de), Gitlab (self-host or hosted), Sourcehut (self-host or hosted eg. sr.ht)
I would not recommend addictive and harmful habits like smoking tobacco/pot and drinking as a coping mechanism, it can go real bad and can make it harder to get out of that hole again.
That is answered in the original post, the author is just doing this for fun and learning. :)
By this logic, you want a complete monopoly of a single platform? Because that’s the only possible way to have “no barrier”. Unless GitHub starts federating with some kind of standardized protocol. This is a huge technological and monetary barrier for GitHub, which is why it will never happen on its own, so if users are not willing to try platform-independent workflows then the problem is frankly not the competing platforms.